#include <boost/function.hpp> 
#include <iostream> 

int main() 
{ 
  try 
  { 
    boost::function<int (const char*)> f; 
    f(""); 
  } 
  catch (boost::bad_function_call &ex) 
  { 
    std::cout << ex.what() << std::endl; 
  } 
} 